“忽略了西方状况的批评家们经常攻击它,认为它是浪费而且危险的.”
首先提炼出句子主体：Critics often attacked it as wasteful and dangerous.
你的疑问中,ignorant of western conditions 是修饰前面Critics的一个定语,即“忽略了西方状况的”.其实有一个短语,be ignorant of…… 忽视某物,将be动词去掉后,置于名词后可以用来修饰该名词.也可以理解成是在两者之间省略了”who are",即Critics （who are）ignorant of western conditions often attacked it as wasteful and dangerous.
同样的情况还可以引申出去.比如be interested in,“对足球感兴趣的男人”就可以翻译成“man interested in football"这样比较简练